Bulk-acoustic wave resonator package

ABSTRACT

A bulk-acoustic wave resonator package includes a package substrate; a cover bonded to the package substrate; an acoustic wave resonator accommodated in an accommodation space defined by the package substrate and the cover; a conductive wire disposed in the accommodation space to electrically connect the acoustic wave resonator to the package substrate; and a bonding portion to fixedly couple the acoustic wave resonator to the package substrate. The bonding portion includes an adhesive member including silicon.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit under 35 USC 119(a) of Korean PatentApplication No. 10-2020-0177601 filed on Dec. 17, 2020 in the KoreanIntellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND 1. Field

The following description relates to a bulk-acoustic wave resonatorpackage.

2. Description of Related Art

In accordance with the trend for the miniaturization of wirelesscommunication devices, the miniaturization of high frequency componenttechnology has been actively demanded. For example, a bulk-acoustic wave(BAW) resonator-type filter using semiconductor thin film wafermanufacturing technology may be used.

A bulk-acoustic wave resonator (BAW) is formed when a thin film typeelement, causing resonance by depositing a piezoelectric dielectricmaterial on a silicon wafer, a semiconductor substrate, and using thepiezoelectric characteristics thereof, is implemented as a filter.

Technological interest in 5G communications has been increasing, and thedevelopment of technologies that can be implemented in candidate bandsis being undertaken.

However, in the case of 5G communication using a Sub 6 GHz (4 to 6 GHz)frequency band, since a bandwidth increases and a communication distancedecreases, signal strength or power of the acoustic wave resonator maybe increased.

Accordingly, there is demand for an acoustic wave resonator for ensuringlong-term operational reliability with small fluctuations in theresonant frequency, even at high power.

SUMMARY

This Summary is provided to introduce a selection of concepts insimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

In one general aspect, a bulk-acoustic wave resonator package includes:a package substrate; a cover bonded to the package substrate; anacoustic wave resonator accommodated in an accommodation space definedby the package substrate and the cover; a conductive wire disposed inthe accommodation space to electrically connect the acoustic waveresonator to the package substrate; and a bonding portion configured tofixedly couple the acoustic wave resonator to the package substrate,wherein the bonding portion includes an adhesive member includingsilicon.

The acoustic wave resonator may include: a support substrate; aresonator including a first electrode, a piezoelectric layer, and asecond electrode sequentially stacked on the support substrate; and ahydrophobic layer disposed along a surface of the resonator.

A cavity may be defined between the resonator and the support substrate,and the hydrophobic layer may be disposed on an inner wall of thecavity.

The hydrophobic layer may include a self-assembled monolayer (SAM)forming material.

The hydrophobic layer may include a fluorine (F) component.

The hydrophobic layer may include fluorocarbon having a silicon head.

The package substrate may include a ceramic substrate.

The conductive wire may include any one material of copper, gold,platinum, and aluminum.

The bulk-acoustic wave resonator package may include: an insertion layerpartially disposed in the resonator, and disposed between the firstelectrode and the piezoelectric layer, and the piezoelectric layer maybe at least partially raised by the insertion layer.

The insertion layer may include an inclined surface, and thepiezoelectric layer may include a piezoelectric portion disposed on thefirst electrode, and an inclined portion disposed on the inclinedsurface of the insertion layer.

In a cross-section cut the resonator, an end of the second electrode maybe disposed on the inclined portion of the piezoelectric layer, or maybe disposed along a boundary between the piezoelectric portion and theinclined portion.

The piezoelectric layer may include an extension portion disposed on anexternal side of the inclined portion, and at least a portion of thesecond electrode may be disposed on the extension portion of thepiezoelectric layer.

The bulk-acoustic wave resonator package may include a Bragg reflectivelayer disposed below the resonator, and the Bragg reflective layer mayinclude a first reflective layer having a first acoustic impedance and asecond reflective layer stacked on the first reflective layer and havinga second acoustic impedance, which is lower than the first acousticimpedance.

A groove-shaped cavity may be disposed on an upper surface of thesupport substrate, and the resonator may be spaced apart from thesupport substrate by the cavity.

The bulk-acoustic wave resonator package may include a connectionsubstrate disposed between the support substrate and the packagesubstrate and mounted on the package substrate, and the bonding portionmay be interposed between the support substrate and the connectionsubstrate.

In another general aspect, a bulk-acoustic wave resonator packageincludes: a package substrate; a support substrate bonded to the packagesubstrate; a resonator disposed on the support substrate, and includinga sequentially stacked first electrode, piezoelectric layer, and secondelectrode; a bonding wire electrically connecting the resonator to thepackage substrate; and a cover configured to accommodate the resonator,the support substrate, and the bonding wire therein and bonded to thepackage substrate, wherein a hydrophobic layer is disposed on a surfaceof the resonator.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a bulk-acoustic wave resonator according to anexample.

FIG. 2 is a cross-sectional view taken along line I-I′ of FIG. 1.

FIG. 3 is a cross-sectional view taken along line II-II′ of FIG. 1.

FIG. 4 is a cross-sectional view taken along line III-III′ in FIG. 1.

FIG. 5 is a cross-sectional view schematically illustrating abulk-acoustic wave resonator package according to an example.

FIG. 6 is a view illustrating a value of measuring a resonant frequencyof the acoustic wave resonator package.

FIG. 7 is a view schematically illustrating a bulk-acoustic waveresonator according to another example.

FIG. 8 is a view schematically illustrating a bulk-acoustic waveresonator according to another example.

FIG. 9 is a view schematically illustrating a bulk-acoustic waveresonator according to another example.

FIG. 10 is a view schematically illustrating a bulk-acoustic waveresonator according to another example.

FIG. 11 is a view schematically illustrating a bulk-acoustic waveresonator package according to another example.

FIG. 12 is a view schematically illustrating a bulk-acoustic waveresonator package according to another example.

Throughout the drawings and the detailed description, the same referencenumerals refer to the same elements. The drawings may not be to scale,and the relative size, proportions, and depiction of elements in thedrawings may be exaggerated for clarity, illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. However, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be apparent to one of ordinary skill inthe art. The sequences of operations described herein are merelyexamples, and are not limited to those set forth herein, but may bechanged as will be apparent to one of ordinary skill in the art, withthe exception of operations necessarily occurring in a certain order.Also, descriptions of functions and constructions that would be wellknown to one of ordinary skill in the art may be omitted for increasedclarity and conciseness.

The features described herein may be embodied in different forms, andare not to be construed as being limited to the examples describedherein. Rather, the examples described herein have been provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the disclosure to one of ordinary skill in the art.

Herein, it is noted that use of the term “may” with respect to anexample or embodiment, e.g., as to what an example or embodiment mayinclude or implement, means that at least one example or embodimentexists in which such a feature is included or implemented while allexamples and embodiments are not limited thereto.

Throughout the specification, when an element, such as a layer, region,or substrate, is described as being “on,” “connected to,” or “coupledto” another element, it may be directly “on,” “connected to,” or“coupled to” the other element, or there may be one or more otherelements intervening therebetween. In contrast, when an element isdescribed as being “directly on,” “directly connected to,” or “directlycoupled to” another element, there can be no other elements interveningtherebetween.

As used herein, the term “and/or” includes any one and any combinationof any two or more of the associated listed items.

Although terms such as “first,” “second,” and “third” may be used hereinto describe various members, components, regions, layers, or sections,these members, components, regions, layers, or sections are not to belimited by these terms. Rather, these terms are only used to distinguishone member, component, region, layer, or section from another member,component, region, layer, or section. Thus, a first member, component,region, layer, or section referred to in examples described herein mayalso be referred to as a second member, component, region, layer, orsection without departing from the teachings of the examples.

Spatially relative terms such as “above,” “upper,” “below,” and “lower”may be used herein for ease of description to describe one element'srelationship to another element as illustrated in the figures. Suchspatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, an element described as being “above” or “upper”relative to another element will then be “below” or “lower” relative tothe other element. Thus, the term “above” encompasses both the above andbelow orientations depending on the spatial orientation of the device.The device may also be oriented in other ways (for example, rotated 90degrees or at other orientations), and the spatially relative terms usedherein are to be interpreted accordingly.

The terminology used herein is for describing various examples only, andis not to be used to limit the disclosure. The articles “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. The terms “comprises,” “includes,”and “has” specify the presence of stated features, numbers, operations,members, elements, and/or combinations thereof, but do not preclude thepresence or addition of one or more other features, numbers, operations,members, elements, and/or combinations thereof.

Due to manufacturing techniques and/or tolerances, variations of theshapes illustrated in the drawings may occur. Thus, the examplesdescribed herein are not limited to the specific shapes illustrated inthe drawings, but include changes in shape that occur duringmanufacturing.

The features of the examples described herein may be combined in variousways as will be apparent after an understanding of the disclosure ofthis application. Further, although the examples described herein have avariety of configurations, other configurations are possible as will beapparent after an understanding of the disclosure of this application.

The drawings may not be to scale, and the relative size, proportions,and depiction of elements in the drawings may be exaggerated forclarity, illustration, and convenience.

FIG. 1 is a plan view of an acoustic wave resonator according to anexample, FIG. 2 is a cross-sectional view taken along I-I′ of FIG. 1,FIG. 3 is a cross-sectional view taken along II-II′ of FIG. 1, and FIG.4 is a cross-sectional view taken along III-III′.

Referring to FIGS. 1 to 4, an acoustic wave resonator 100 may be abulk-acoustic wave (BAW) resonator, and may include a support substrate110, an insulating layer 115, a resonator 120, and hydrophobic layer130.

The support substrate 110 may be a silicon substrate. For example, asilicon wafer may be used as the support substrate 110, or a silicon oninsulator (SOI)-type substrate may be used.

The insulating layer 115 may be provided on an upper surface of thesupport substrate 110 to electrically isolate the support substrate 110and the resonator 120. The insulating layer 115 prevents the supportsubstrate 110 from being etched by an etching gas when a cavity C isformed in a manufacturing process of the acoustic wave resonator.

In this case, the insulating layer 115 may be formed of at least one ofsilicon dioxide (SiO₂), silicon nitride (Si₃N₄), aluminum oxide (Al₂O₃),and aluminum nitride (AlN), and may be formed through any one process ofchemical vapor deposition, RF magnetron sputtering, and evaporation.

A support layer 140 may be formed on the insulating layer 115, and maybe disposed around the cavity C and an etch stop portion 145 to surroundthe cavity C and the etch stop portion 145 inside the support layer 140.

The cavity C may be formed as an empty space, and may be formed byremoving a portion of a sacrificial layer, and the support layer 140 maybe formed as a remaining portion of the sacrificial layer.

The support layer 140 may be formed of a material such as polysilicon ora polymer, which may be relatively easy to etch. However, the supportlayer 140 is not limited to such materials.

The etch stop portion 145 is disposed along a boundary of the cavity C.The etch stop portion 145 may be provided to prevent etching from beingperformed beyond a cavity region in a process of forming the cavity C.

A membrane layer 150 may be formed on the support layer 140, and form anupper surface of the cavity C. Therefore, the membrane layer 150 mayalso be formed of a material that is not easily removed in the processof forming the cavity C.

For example, when a halide-based etching gas such as fluorine (F),chlorine (CI), or the like is used to remove a portion (e.g., a cavityregion) of the support layer 140, the membrane layer 150 may be formedof a material having low reactivity with the etching gas. For example,the membrane layer 150 may include at least one of silicon dioxide(SiO₂) and silicon nitride (Si₃N₄).

The membrane layer 150 may be formed of a dielectric layer containing atleast one material of magnesium oxide (MgO), zirconium oxide (ZrO₂),aluminum nitride (AlN), lead zirconate titanate (PZT), gallium arsenide(GaAs), hafnium oxide (HfO₂), and aluminum oxide (Al₂O₃), titanium oxide(TiO₂), and zinc oxide (ZnO), or a metal layer containing at least onematerial of aluminum (Al), nickel (Ni), chromium (Cr), platinum (Pt),gallium (Ga), and hafnium (Hf). However, a configuration of the membranelayer 150 is not limited thereto.

The resonator 120 includes a first electrode 121, a piezoelectric layer123, and a second electrode 125. The resonator 120 is configured suchthat the first electrode 121, the piezoelectric layer 123, and thesecond electrode 125 are stacked in order from a bottom layer.Therefore, the piezoelectric layer 123 in the resonator 120 is disposedbetween the first electrode 121 and the second electrode 125.

Since the resonator 120 is formed on the membrane layer 150, themembrane layer 150, the first electrode 121, the piezoelectric layer123, and the second electrode 125 are sequentially stacked on thesupport substrate 110, to form the resonator 120.

The resonator 120 may resonate the piezoelectric layer 123 according tosignals applied to the first electrode 121 and the second electrode 125to generate a resonant frequency and an anti-resonant frequency.

The resonator 120 may be divided into a central portion S in which thefirst electrode 121, the piezoelectric layer 123, and the secondelectrode 125 are stacked to be substantially flat, and an extensionportion E in which an insertion layer 170 is interposed between thefirst electrode 121 and the piezoelectric layer 123.

The central portion S is a region disposed in a center of the resonator120, and the extension portion E is a region disposed along a peripheryof the central portion S. Therefore, the extension portion E is a regionextended from the central portion S externally, and may be a regionformed to have a continuous annular shape along the periphery of thecentral portion S. However, if necessary, the extension portion E may beconfigured to have a discontinuous annular shape, in which some regionsare disconnected.

Accordingly, as shown in FIG. 2, in the cross-section of the resonator120 cut so as to cross the central portion S, the extension portion E isdisposed on both ends of the central portion S, respectively. Theinsertion layer 170 is disposed on both sides of the extension portion Edisposed on both ends of the central portion S.

The insertion layer 170 has an inclined surface L of which a thicknessbecomes greater as a distance from the central portion S increases.

In the extension portion E, the piezoelectric layer 123 and the secondelectrode 125 are disposed on the insertion layer 170. Therefore, thepiezoelectric layer 123 and the second electrode 125 located in theextension portion E have an inclined surface along the shape of theinsertion layer 170.

The extension portion E is included in the resonator 120, andaccordingly, resonance may also occur in the extension portion E.However, the configuration is not limited thereto, and resonance may notoccur in the extension portion E depending on the structure of theextension portion E, but resonance may occur only in the central portionS.

The first electrode 121 and the second electrode 125 may be formed of aconductor, for example, may be formed of gold, molybdenum, ruthenium,iridium, aluminum, platinum, titanium, tungsten, palladium, tantalum,chromium, nickel, or a metal containing at least one thereof, but arenot limited to such a configuration.

In the resonator 120, the first electrode 121 is formed to have a largerarea than the second electrode 125, and a first metal layer 180 isdisposed along an outer periphery of the first electrode 121 on thefirst electrode 121. Therefore, the first metal layer 180 may bedisposed to be spaced apart from the second electrode 125 by apredetermined distance, and may be disposed in a form surrounding theresonator 120.

Since the first electrode 121 is disposed on the membrane layer 150, thefirst electrode 121 is formed to be entirely flat. On the other hand,since the second electrode 125 is disposed on the piezoelectric layer123, curving may be formed in the second electrode 125 corresponding tothe shape of the piezoelectric layer 123.

The first electrode 121 may be used as any one of an input electrode andan output electrode for inputting and outputting an electrical signalsuch as a radio frequency (RF) signal, or the like.

The second electrode 125 is entirely disposed in the central portion S,and partially disposed in the extension portion E. Accordingly, thesecond electrode 125 may be divided into a portion disposed on apiezoelectric portion 123 a of the piezoelectric layer 123, and aportion disposed on a curved portion 123 b of the piezoelectric layer123.

More specifically, in the present example, the second electrode 125 isdisposed to cover an entirety of the piezoelectric portion 123 a and aportion of an inclined portion 1231 of the piezoelectric layer 123.Accordingly, a portion of the second electrode 125 (portion 125 a shownin FIG. 4) disposed in the extension portion E is formed to have asmaller area than an inclined surface of the inclined portion 1231, andthe second electrode 125 in the resonator 120 is formed to have asmaller area than the piezoelectric layer 123.

Accordingly, as shown in FIG. 2, in a cross-section of the resonator 120cut so as to cross the central portion S, an end of the second electrode125 may be disposed in the extension portion E. The end of the secondelectrode 125 disposed in the extension portion E may be disposed suchthat at least a portion thereof overlaps the insertion layer 170. Forexample, ‘overlap’ means that if the second electrode 125 was to beprojected onto a plane on which the insertion layer 170 is disposed, ashape of the second electrode 125 projected on the plane would overlapthe insertion layer 170.

The second electrode 125 may be used as any one of an input electrodeand an output electrode for inputting and outputting an electricalsignal such as a radio frequency (RF) signal, or the like. That is, whenthe first electrode 121 is used as the input electrode, the secondelectrode 125 may be used as the output electrode, and when the firstelectrode 121 is used as the output electrode, the second electrode 125may be used as the input electrode.

As illustrated in FIG. 4, when the end of the second electrode 125 ispositioned on the inclined portion 1231 of the piezoelectric layer 123,since a local structure of an acoustic impedance of the resonator 120 isformed in a sparse/dense/sparse/dense structure from the central portionS, a reflective interface reflecting a lateral wave inwardly of theresonator 120 increases. Therefore, since most lateral waves could notflow outwardly of the resonator 120, and are reflected and then flow toan interior of the resonator 120, the performance of the acoustic waveresonator may be improved.

The piezoelectric layer 123 is a portion converting electrical energyinto mechanical energy in a form of elastic waves through apiezoelectric effect, and is formed on the first electrode 121 and theinsertion layer 170.

As a material of the piezoelectric layer 123, zinc oxide (ZnO), aluminumnitride (AlN), doped aluminum nitride, lead zirconate titanate, quartz,and the like can be selectively used. In the case of doped aluminumnitride, a rare earth metal, a transition metal, or an alkaline earthmetal may be further included. The rare earth metal may include at leastone of scandium (Sc), erbium (Er), yttrium (Y), and lanthanum (La). Thetransition metal may include at least one of hafnium (Hf), titanium(Ti), zirconium (Zr), tantalum (Ta), and niobium (Nb). In addition, thealkaline earth metal may include magnesium (Mg).

In order to improve piezoelectric properties, when a content of elementsdoped with aluminum nitride (AlN) is less than 0.1 at %, a piezoelectricproperty higher than that of aluminum nitride (AlN) cannot be realized.When the content of the elements exceeds 30 at %, it is difficult tofabricate and control the composition for deposition, such that unevencrystalline phases may be formed.

Therefore, in the present example, the content of elements doped withaluminum nitride (AlN) may be in a range of 0.1 to 30 at %.

In the present example, the piezoelectric layer is doped with scandium(Sc) in aluminum nitride (AlN). In this case, a piezoelectric constantmay be increased to increase Kt² of the acoustic wave resonator.

The piezoelectric layer 123 includes the piezoelectric portion 123 adisposed in the central portion S and the curved portion 123 b disposedin the extension portion E.

The piezoelectric portion 123 a is a portion directly stacked on theupper surface of the first electrode 121. Therefore, the piezoelectricportion 123 a is interposed between the first electrode 121 and thesecond electrode 125 and is formed as a flat shape, together with thefirst electrode 121 and the second electrode 125.

The curved portion 123 b may be defined as a region extending from thepiezoelectric portion 123 a externally and positioned in the extensionportion E.

The curved portion 123 b is disposed on the insertion layer 170, and isformed in a shape in which the upper surface thereof is raised along theshape of the insertion layer 170. Accordingly, the piezoelectric layer123 is curved at a boundary between the piezoelectric portion 123 a andthe curved portion 123 b, and the curved portion 123 b is raisedcorresponding to the thickness and shape of the insertion layer 170.

The curved portion 123 b may be divided into the inclined portion 1231and an extension portion 1232.

The inclined portion 1231 is a portion formed to be inclined along theinclined surface L of the insertion layer 170. The extension portion1232 is a portion extending from the inclined portion 1231 externally.

The inclined portion 1231 may be formed to be parallel to the inclinedsurface L of the insertion layer 170, and an inclination angle of theinclined portion 1231 may be formed to be the same as an inclinationangle of the inclined surface L of the insertion layer 170.

The insertion layer 170 is disposed along a surface formed by themembrane layer 150, the first electrode 121, and the etch stop portion145. Therefore, the insertion layer 170 is partially disposed in theresonator 120, and is disposed between the first electrode 121 and thepiezoelectric layer 123.

The insertion layer 170 is disposed at a periphery of the centralportion S to support the curved portion 123 b of the piezoelectric layer123. Accordingly, the curved portion 123 b of the piezoelectric layer123 may be divided into the inclined portion 1231 and the extensionportion 1232 according to the shape of the insertion layer 170.

In the present example, the insertion layer 170 is disposed in a regionexcept for the central portion S. For example, the insertion layer 170may be disposed on the support substrate 110 in an entire region exceptfor the central portion S, or in some regions.

The insertion layer 170 is formed to have a thickness becoming greateras a distance from the central portion S increases. Thereby, theinsertion layer 170 is formed of the inclined surface L having aconstant inclination angle Θ of the side surface disposed adjacent tothe central portion S.

When the inclination angle Θ of the side surface of the insertion layer170 is formed to be smaller than 5°, in order to manufacture the same,since the thickness of the insertion layer 170 should be formed to bevery thin or an area of the inclined surface L should be formed to beexcessively large, it is practically difficult to be implemented.

In addition, when the inclination angle Θ of the side surface of theinsertion layer 170 is formed to be greater than 70°, the inclinationangle of the piezoelectric layer 123 or the second electrode 125 stackedon the insertion layer 170 is also formed to be greater than 70°. Inthis case, since the piezoelectric layer 123 or the second electrode 125stacked on the inclined surface L is excessively curved, cracks may begenerated in the curved portion.

Therefore, in the present example, the inclination angle Θ of theinclined surface L is formed in a range of 5° or more and 70° or less.

The inclined portion 1231 of the piezoelectric layer 123 is formed alongthe inclined surface L of the insertion layer 170, and thus is formed atthe same inclination angle as the inclined surface L of the insertionlayer 170. Therefore, the inclination angle of the inclined portion 1231is also formed in a range of 5° or more and 70° or less, similarly tothe inclined surface L of the insertion layer 170. The configuration mayalso be equally applied to the second electrode 125 stacked on theinclined surface L of the insertion layer 170.

The insertion layer 170 may be formed of a dielectric material such assilicon oxide (SiO₂), aluminum nitride (AlN), aluminum oxide (Al₂O₃),silicon nitride (Si₃N₄), magnesium oxide (MgO), zirconium oxide (ZrO₂),lead zirconate titanate (PZT), gallium arsenide (GaAs), gallium arsenide(GaAs), hafnium oxide (HfO₂), titanium oxide (TiO₂), zinc oxide (ZnO),or the like, but may be formed of a material, different from that of thepiezoelectric layer 123.

The insertion layer 170 may be implemented with a metal material. Whenthe acoustic wave resonator of the present example is used for 5Gcommunications, heat generated from the resonator 120 needs to besmoothly discharged because a lot of heat is generated from theresonator 120. To this end, the insertion layer 170 of the presentexample may be made of an aluminum alloy material containing scandium(Sc).

The resonator 120 may be disposed to be spaced apart from the supportsubstrate 110 through the cavity C formed as a void.

The cavity C may be formed by removing a portion of the support layer140 by supplying an etching gas (or an etching solution) to an inlethole (H in FIGS. 1 and 3) during a manufacturing process of the acousticwave resonator 100.

Accordingly, the cavity C is composed of a space in which an uppersurface (a ceiling surface) and a side surface (a wall surface) areformed by the membrane layer 150, and a bottom surface thereof is formedby the support substrate 110 or the insulating layer 115. The membranelayer 150 may be formed only on the upper surface (the ceiling surface)of the cavity C according to the order of the manufacturing method.

A protective layer 160 is disposed along the surface of the acousticwave resonator 100 to protect the acoustic wave resonator 100 from theoutside. The protective layer 160 may be disposed along a surface formedby the second electrode 125 and the curved portion 123 b of thepiezoelectric layer 123.

The protective layer 160 may be partially removed for frequency controlin a final process during the manufacturing process. For example, thethickness of the protective layer 160 may be controlled throughfrequency trimming during the manufacturing process.

To this end, the protective layer 160 may include one of silicon oxide(SiO₂), silicon nitride (Si₃N₄), magnesium oxide (MgO), zirconium oxide(ZrO₂), aluminum nitride (AlN), lead zirconate titanate (PZT), galliumArsenic (GaAs), hafnium oxide (HfO₂), aluminum oxide (Al₂O₃), titaniumoxide (TiO₂), zinc oxide (ZnO), amorphous silicon (a-Si), andpolycrystalline silicon (p-Si), suitable for frequency trimming, but isnot limited to such materials.

The first electrode 121 and the second electrode 125 may extendexternally of the resonator 120. The first metal layer 180 and a secondmetal layer 190 may be disposed on an upper surface of the extensionportion E, respectively.

The first metal layer 180 and the second metal layer 190 may be made ofany one material of gold (Au), a gold-tin (Au—Sn) alloy, copper (Cu), acopper-tin (Cu—Sn) alloy, and aluminum (Al), and an aluminum alloy.Here, the aluminum alloy may be an aluminum-germanium (Al—Ge) alloy oran aluminum-scandium (Al—Sc) alloy.

The first metal layer 180 and the second metal layer 190 may serve to aconnection wiring electrically connecting the electrodes 121 and 125 ofthe acoustic wave resonator 100 on the substrate 110 and electrodes ofother acoustic wave resonators disposed adjacent to each other.

At least a portion of the first metal layer 180 may be in contact withthe protective layer 160 and may be bonded to the first electrode 121.

In the resonator 120, the first electrode 121 may be formed to have alarger area than the second electrode 125, and the first metal layer 180may be formed on a peripheral portion of the first electrode 121.

Therefore, the first metal layer 180 may be disposed at the periphery ofthe resonator 120, and accordingly, may be disposed to surround thesecond electrode 125. However, the configuration is not limited thereto.

In the acoustic wave resonator 100, the hydrophobic layer 130 may bedisposed on a surface of the protective layer 160 and an inner wall ofthe cavity C.

When an acoustic wave resonator is used in a humid environment or isleft at room temperature for a long period of time, a hydroxyl group (OHgroup) is adsorbed to the protective layer 160 of the acoustic waveresonator such that a problem in which frequency fluctuations increasedue to mass loading or resonance performance deterioration, may occur.

For example, when a hydrophobic layer 130 is not formed on a surface ofthe bulk-acoustic wave resonator, a hydroxyl group (an OH group) may bemore easily adsorbed to the protective layer 160, to form hydroxylate.Since hydroxylate has a high surface energy and is unstable, it attemptsto lower the surface energy by adsorbing water, and the like, resultingin mass loading.

On the other hand, when the hydrophobic layer 130 is provided on asurface of the acoustic wave resonator, since the surface energy is lowand stable, there is no need to lower the surface energy by adsorbingwater, a hydroxyl group (OH group), and the like. Therefore, thehydrophobic layer 130 may serve to suppress adsorption of water,hydroxyl group (OH group), and the like, thereby significantly reducingfrequency fluctuations, and thus maintaining uniform resonatorperformance.

The hydrophobic layer 130 may be formed of a self-assembled monolayer(SAM) formation material, rather than a polymer. When the hydrophobiclayer 130 is formed of a polymer, mass due to the polymer may affect theresonator 120. However, in the acoustic wave resonator according to anexample, since the hydrophobic layer 130 is formed of a self-assembledmonolayer, it is possible to significantly reduce frequency fluctuationsof the acoustic wave resonator. In addition, the thickness of thehydrophobic layer 130 according to the position in the cavity C may beuniformly formed.

The hydrophobic layer 130 may be formed by performing vapor depositionon a precursor for having hydrophobicity. In this case, the hydrophobiclayer 130 may be deposited as a monolayer having a thickness of 100 Å orless (e.g., several Å to tens of Å). As the precursor material forhaving hydrophobicity, it may be formed of a material having a contactangle of 90° or more with water after deposition. For example, thehydrophobic layer 130 may contain a fluorine (F) component, and mayinclude fluorine (F) and silicon (Si). Specifically, fluorocarbon havinga silicon head may be used, but the configuration is not limitedthereto.

In order to improve adhesion between the self-assembled monolayerconstituting the hydrophobic layer 130 and the protective layer 160, abonding layer (not shown) may first be formed on a surface of theprotective layer 160 prior to forming the hydrophobic layer 130.

The bonding layer may be formed by performing vapor deposition on aprecursor having a hydrophobic functional group on a surface of theprotective layer 160.

As the precursor material used for deposition of the bonding layer,hydrocarbon having a silicon head, or siloxane having a silicon head maybe used, but is not limited thereto.

Since the hydrophobic layer 130 is formed after the first metal layer180 and the second metal layer 190 are formed, the hydrophobic layer 130may be formed along surfaces of the protective layer 160, the firstmetal layer 180, and the second metal layer 190.

In the drawings, an example in which the hydrophobic layer 130 is notdisposed on the surfaces of the first metal layer 180 and the secondmetal layer 190 is illustrated, but the configuration is not limitedthereto. The hydrophobic layer 130 may also be disposed on the surfacesof the first metal layer 180 and the second metal layer 190, as needed.

The hydrophobic layer 130 may be disposed not only on an upper surfaceof the protective layer 160, but also on an inner surface of the cavityC.

The hydrophobic layer 130 formed in the cavity C may be formed over anentire inner wall forming the cavity C. Accordingly, the hydrophobiclayer 130 may also be formed on a lower surface of the membrane layer150 forming a lower surface of a resonator 120.

In this case, adsorption of hydroxyl groups to a lower portion of theresonator 120 can be suppressed.

The adsorption of hydroxyl groups may occur in the cavity C as well asin the protective layer 160. Therefore, in order to minimize the massloading and the corresponding frequency drop due to the adsorption ofhydroxyl groups, it is preferable to block adsorption of hydroxyl groupsnot only on the protective layer 160 but also on an upper surface of thecavity C (the lower surface of the membrane layer), which is the lowersurface of the resonator.

In addition thereto, when the hydrophobic layer 130 is formed on theupper/lower surface or side surface of the cavity C, it may also providean effect of suppressing an occurrence of a stiction phenomenon in whichthe resonator 120 sticks to the insulating layer 115 due to surfacetension in a wet process or a cleaning process after the cavity C isformed.

Meanwhile, in the present embodiment, a case in which the hydrophobiclayer 130 is formed over the entire inner wall of the cavity C isillustrated as an example, but is not limited thereto, and variousmodifications, such as a hydrophobic layer may be formed only on theupper surface of the cavity C, or a hydrophobic layer 130 may be formedon at least a portion of the lower surface and the side surface thereof,may be made.

Next, an acoustic wave resonator package according to an example will bedescribed.

FIG. 5 is a cross-sectional view schematically illustrating an acousticwave resonator package according to an example.

Referring to FIG. 5, an acoustic wave resonator package 10 includes atleast one of acoustic wave resonators 100 described above. In addition,the acoustic wave resonator package 100 may include a package substrate50 and a cover 60.

The acoustic wave resonator 100 may be bonded to the package substrate50 via a bonding portion 70.

The acoustic wave resonator 100 may be bonded to the package substrate50 through a silicon-based adhesive member 71. Accordingly, the bondingportion 70 may include a material including silicon.

The package substrate 50 may be formed of a ceramic substrate. However,the configuration is not limited thereto, and various types of supportsubstrates well known in the art (e.g., printed circuit boards, flexiblesubstrates, glass substrates, ceramic substrates, or the like) may beused.

The package substrate 50 may be a double-sided substrate in which awiring layer is formed on both surfaces of one insulating layer.However, the configuration is not limited thereto, and a multilayersubstrate formed by repeatedly stacking a plurality of insulating layersand a plurality of wiring layers may be used.

At least one electrode pad 45 may be formed on a surface of the packagesubstrate 50. The electrode pad 45 may be electrically connected to theacoustic wave resonator 100 through a conductive wire 40.

In order to protect the resonator of the acoustic wave resonator 100from an external environment, the cover 60 may be coupled to the packagesubstrate 50.

The cover 60 may be formed in a form of a cap having an internal spacein which the acoustic wave resonator 100 is accommodated. Accordingly,the cover 60 may include a sidewall and an upper surface portionconnecting an upper portion of the sidewall, and may be bonded to thepackage substrate 50 in a form in which the sidewall thereof surroundsthe acoustic wave resonator 100.

Accordingly, the acoustic wave resonator 100 may be accommodated in anaccommodation space P formed by the cover 60 and the package substrate50.

The cover 60 may be formed of a metal material, and may be bonded to thepackage substrate 50 through metal bonding. For example, a bondingmember 65 for bonding the cover 60 and the package substrate 50 to eachother may be interposed between the cover 60 and the package substrate50, and a lower surface of the sidewall of the cover 60 may be used as abonding surface with the package substrate 50.

As the acoustic wave resonator 100 is bonded to the package substrate50, it is not easy to electrically connect the acoustic wave resonator100 to the package substrate 50 through a lower surface of the acousticwave resonator 100. Accordingly, the acoustic wave resonator 100 may beelectrically connected to the package substrate 50 through theconductive wire 40. For example, one end of the conductive wire 40 maybe bonded to the support substrate 110 of the acoustic wave resonator100, and the other end of the conductive wire 40 may be bonded to theelectrode pad 45 of the package substrate 50 to electrically connect theacoustic wave resonator 100 to the package substrate 50.

The conductive wire 40 may be made of any one of copper, gold, platinum,and aluminum. For example, as the conductive wire 40, a known bondingwire may be used, but is not limited thereto.

The acoustic wave resonator package 10 may be manufactured by bondingthe acoustic wave resonator 100 to the package substrate 50 and thenbonding the cover 60 to the package substrate 50.

However, in the process of bonding the acoustic wave resonator 100 tothe package substrate 50, there is a problem in that particles such asmist and fumes generated by the adhesive member may be adsorbed onto thesurface of the acoustic wave resonator 100. The particles change mass ofthe resonator of the acoustic wave resonator 100 and act as a factor toincrease the fluctuation amount and standard deviation of the resonantfrequency.

Therefore, if an amount of particles adhering to the surface of theresonator of the acoustic wave resonator 100 cannot be controlled belowa certain level, a desired resonant frequency may not be obtained andmay affect a yield of a product.

Accordingly, in order to suppress the particles generated by theadhesive member from being adsorbed onto the surface of the resonator ofthe acoustic wave resonator 100, the acoustic wave resonator 100includes a hydrophobic layer, as described above. In addition, it isformed such that the bonding portion 70 includes the adhesive member 71made of a silicone-based material.

When the fine particles (or an organic matter), described above areadsorbed to an interface of a certain material, chemical interaction(chemisorption) is performed in advance. Chemical interaction orchemical adsorption is characterized by strong interactions betweenatoms or molecules.

On the other hand, in physisorption, the interaction between atoms ormolecules is weak compared to chemical adsorption, whereas in the caseof polymers, the molecular chain is long, so an adsorption interface canbe formed in a form of a multilayer structure.

When the acoustic wave resonator 100 is bonded to the package substrate50 using an adhesive member 71, in order to minimize a change in mass ofthe resonator of the acoustic wave resonator 100 due to the organicparticles described above, it is necessary to minimize the chemicaladsorption between the organic matter and the acoustic wave resonator100 first.

To this end, the acoustic wave resonator 100 is provided with theabove-described hydrophobic layer on the surface thereof. When thehydrophobic layer is provided, since it is possible to suppress ahydroxyl group adsorption material from being generated by the adhesivemember 71 from being adsorbed to the surface of the resonator of theacoustic wave resonator 100, chemical adsorption between the organicmatter and the acoustic wave resonator 100 may be minimized.

In the acoustic wave resonator package 10, in order to minimize physicaladsorption between the organic material and the acoustic wave resonator100, an organic material composed of a single molecule, not a polymer,or an organic material with a short molecular chain is used as anadhesive member 71. Specifically, in the present example, the bondingportion 70 between the support substrate 110 of the acoustic waveresonator 100 and the package substrate 50 may be formed of a materialhaving silicon. Accordingly, it is possible to suppress the organicmaterial from being coupled to the surface of the resonator of theacoustic wave resonator 100 in a form of a multilayer structure duringthe physical adsorption process, thereby minimizing the mass load of theresonator of the acoustic wave resonator 100.

FIG. 6 is a view illustrating a value of measuring the resonantfrequency of the acoustic wave resonator package. After a bondingportion 70 is formed with an epoxy-based adhesive member and asilicone-based adhesive member, a frequency fluctuation amount andstandard deviation of the acoustic wave resonator package were measured,and results according to whether or not a hydrophobic layer is presentwere also measured and shown.

The frequency fluctuation refers to a difference in frequency between aresonant frequency before the acoustic wave resonator is packaged(before bonding the package substrate and the support substrate) and aresonant frequency after the acoustic wave resonator is packaged, and anaverage value thereof was shown. In addition, the standard deviationrefers to dispersion of the frequency fluctuation amount, and afluctuation range indicates a range of a maximum value and a minimumvalue for the frequency difference between the resonant frequency beforethe acoustic wave resonator is packaged and the resonant frequency afterthe packaging is completed.

In a Reference Example in FIG. 6, 100 samples were measured, and afterbonding the acoustic wave resonator 100 without a hydrophobic layer tothe package substrate 50 using an epoxy-based adhesive member, aresonant frequency was measured.

In the case of the Reference Example, it can be seen that a frequencyfluctuation amount was measured as an average of 5.30 MHz, standarddeviation was 1.86, and a fluctuation range was 10.42 MHz, which is verylarge.

In Comparative Example 1, 60 samples were measured, and after bondingthe acoustic wave resonator 100 having the hydrophobic layer 130 to thepackage substrate 50 using an epoxy-based adhesive member, a resonantfrequency was measured.

In the case of Comparative Example 1, it can be seen that a frequencyfluctuation amount was measured as an average of 5.31 MHz, which is notsignificantly different from the reference example, but standarddeviation was 0.86, and a fluctuation range was 7.81 MHz, which isslightly improved compared to the Reference example.

It can be seen as a result of minimizing chemical adsorption ofparticles through the hydrophobic layer 130. However, considering thatthe frequency fluctuation amount is still large and the fluctuationrange is not significantly improved, in the process of curing theepoxy-based adhesive member, it can be understood that particles of apolymer component with a long molecular chain are physically adsorbed onthe surface of the resonator 120.

In Comparative Example 2, 60 samples were measured, and after bondingthe acoustic wave resonator 100 without the hydrophobic layer 130 to thepackage substrate 50 using a silicon-based adhesive member 71, aresonant frequency was measured.

It can be seen that the frequency fluctuation amount according toComparative Example 2 was measured as an average of 3.5 MHz, andstandard deviation was 0.16, which is slightly improved compared to theReference example, and a fluctuation range was 4.67 MHz, which is alsoslightly improved compared to the Reference Example.

In the case of Comparative Example 2, overall characteristics of theacoustic wave resonator 100 were improved by suppressing physicaladsorption of fine particles by using a silicon-based adhesive member.Therefore, it can be seen that the fluctuation of the resonant frequencyis greatly improved only by suppressing the physical adsorption of theparticles by using the silicon-based adhesive member 71. However, it canbe seen that the fluctuation range is still large because the chemicaladsorption cannot be suppressed.

In Comparative Example 3, 120 samples were measured, and after bondingthe acoustic wave resonator 100 having the hydrophobic layer 130 to thepackage substrate 50 using a silicon-based adhesive member 71, aresonant frequency was measured.

It can be seen that a frequency fluctuation according to ComparativeExample 3 was measured as an average of 1.15 MHz and standard deviationof 0.13, which were measured to be very low, and a variation range wasalso 1.2 MHz, which was significantly improved compared to the ReferenceExample or other Comparative examples.

In Comparative Example 3, physical adsorption of fine particles wassuppressed by using the silicon-based adhesive member 71, and at thesame time, chemical adsorption was suppressed through the hydrophobiclayer 130, and in this case, it was confirmed that the fluctuation ofthe resonant frequency was significantly reduced.

Accordingly, in the acoustic wave resonator package according to thevarious examples, the support substrate 110 and the package substrate 50may be bonded to each other via an adhesive member 71 including silicon,and a hydrophobic layer 130 may further be provided on a surface of theresonator 120.

In addition, a ceramic filler may be added to the adhesive member 71including silicon to improve thermal conductivity of the bonding portion70. As the ceramic filler, SiO₂, Al₂O₃, TiO₂, Si₃N₄, AlN, BN, or thelike may be used, but is not limited thereto.

FIG. 7 is a cross-sectional view schematically illustrating an acousticwave resonator according to another example.

Referring to FIG. 7, in the acoustic wave resonator according to thepresent example, in a cross-section of the resonator 120 cut to crossthe central portion S, an end portion of the second electrode 125 isformed only on an upper surface of the piezoelectric portion 123 a ofthe piezoelectric layer 123, and is not formed on the curved portion 123b. Accordingly, the end of the second electrode 125 is disposed along aboundary between the piezoelectric portion 123 a and the inclinedportion 1231.

FIG. 8 is a cross-sectional view schematically illustrating an acousticwave resonator according to another example.

In the acoustic wave resonator shown in the present example, a secondelectrode 125 is disposed on the entire upper surface of thepiezoelectric layer 123 in the resonator 120, and accordingly, thesecond electrode 125 is formed not only on the inclined portion 1231 ofthe piezoelectric layer 123, but also on the extension portion 1232thereof.

As such, the acoustic wave resonator according to the various examplesmay be modified into various shapes as needed.

FIG. 9 is a cross-sectional view schematically illustrating an acousticwave resonator according to another example.

Referring to FIG. 9, the acoustic wave resonator according to thepresent example is formed similarly to the acoustic wave resonator shownin FIG. 2, does not include a cavity (C in FIG. 2), and includes a Braggreflector layer 117.

The Bragg reflective layer 117 may be disposed inside the supportsubstrate 110, and may be formed by alternately staking a firstreflective layer B1 having a high acoustic impedance and a secondreflective layer B2 having a low acoustic impedance below the resonator120.

In this case, the thickness of the first reflective layer B1 and thesecond reflective layer B2 may be defined to fit a specific wavelength,so that an acoustic wave may be reflected in a vertical direction towardthe resonator 120, so that it can block that the acoustic wave is leakedto a lower side of the support substrate 110.

To this end, the first reflective layer B1 may be made of a materialhaving a higher density than that of the second reflective layer B2. Forexample, any one of W, Mo, Ru, Ir, Ta, Pt, and Cu may be selectivelyused as the material of the first reflective layer B1. In addition, thesecond reflective layer B2 is made of a material having a lower densitythan that of the first reflective layer B1, and for example, any one ofSiO₂, Si₃N₄, and AlN may be selectively used. However, the configurationis not limited thereto.

FIG. 10 is a cross-sectional view schematically illustrating an acousticwave resonator according to another example.

Referring to FIG. 10, the acoustic wave resonator according to thepresent example is formed similarly to the acoustic wave resonator shownin FIG. 2, and in the acoustic wave resonator, a cavity C is not formedby partially removing the supporting substrate 110 without forming thecavity C on the supporting substrate 110.

The cavity C of the present example may be formed by partially etchingan upper surface of the support substrate 110. Both dry etching and wetetching may be used for etching the support substrate 110. A barrierlayer 113 may be formed on an inner surface of the cavity (C). Thebarrier layer 113 may protect the support substrate 110 from an etchingsolution used in the process of forming the resonator 120.

The barrier layer 113 may be formed of a dielectric layer such as AlN orSiO₂, or the like, but is not limited to such materials, and variousmaterials may be used as long as it can protect the support substrate110 from an etching solution.

In addition, a hydrophobic layer 130 may be formed on the barrier layer113.

The acoustic wave resonator shown in FIGS. 7 to 10 is a portion disposedin part A of FIG. 5, and may be bonded to the package substrate 50through a silicon-based adhesive member 71, respectively, and ahydrophobic layer 130 may be disposed on a surface of the resonator.

FIG. 11 is a cross-sectional view schematically illustrating an acousticwave resonator package according to another example.

Referring to FIG. 11, the acoustic wave resonator package of the presentexample may include a bonding portion 70, fixing the acoustic waveresonator 100 to the package substrate 50, an adhesive member 71, aconnection substrate 80, and a connection member 90.

The connection substrate 80 may be disposed between the supportsubstrate 110 of the acoustic wave resonator 100 and the packagesubstrate 50 and mounted on the package substrate 50.

In the present example, the connection substrate 80 may be adouble-sided substrate in which a wiring layer is formed on bothsurfaces of one insulating layer. However, the configuration is notlimited thereto, and a multilayer substrate formed by repeatedlystacking a plurality of insulating layers and a plurality of wiringlayers may be used.

In addition, various types of support substrates well known in the art(e.g., printed circuit boards, flexible substrates, glass substrates,ceramic substrates, or the like) may be used as the connection substrate80.

One or a plurality of acoustic wave resonators 100 may be disposed onthe connection substrate 80. Accordingly, the plurality of acoustic waveresonators 100 may be electrically connected to each other through theconnection substrate 80.

The acoustic wave resonator 100 may be bonded to the connectionsubstrate 80 through an adhesive member 71, and may be electricallyconnected to the connection substrate 80 through a conductive wire 40.Accordingly, the package substrate 50 may be electrically connected tothe acoustic wave resonator via the conductive wire 40 and theconnection substrate 80. However, the configuration is not limitedthereto, and if necessary, it may also be configured such that at leastone conductive wire directly connects the acoustic wave resonator 100and the package substrate 50.

As the adhesive member 71, a silicon-based material including siliconmay be used as in the above-described examples, and thus, the sameeffect as in the above-described embodiments may be provided.

In the present example, the connection substrate 80 and the packagesubstrate 50 may be electrically and physically connected through aconductive connection member 90 such as solder. For example, after asolder paste is disposed between the connection substrate 80 and thepackage substrate 50, the conductive connection member 90 may be formedthrough a reflow process. Accordingly, the connection substrate 80 mayelectrically connect the acoustic wave resonator 100 and the packagesubstrate 50.

However, the configuration is not limited thereto, and it is alsopossible to bond the connection substrate 80 and the package substrate50 to each other using a silicon-based material such as the adhesivemember 71. In this case, the connection substrate 80 and the packagesubstrate 50 may be electrically connected to each other through aconductive wire.

FIG. 12 is a cross-sectional view schematically illustrating an acousticwave resonator package according to another example.

Referring to FIG. 12, in the acoustic wave resonator package of thepresent example, an accommodation space P may be provided in the packagesubstrate 80. The acoustic wave resonator 100 may be accommodated in theaccommodation space P and coupled to the package substrate 50.

The accommodation space P may be formed in a form of a groove, and maybe formed as a space having a size for completely accommodating theacoustic wave resonator 100. Accordingly, the acoustic wave resonator100 accommodated in the accommodation space P may not protrude to anexternal portion of the package substrate 50.

A step may be formed on a side surface of the accommodation space P, andan electrode pad 45 to which a conductive wire is bonded may be disposedon one surface of the step. However, the configuration is not limitedthereto, and the electrode pads may be disposed at various positions asneeded, such as forming an electrode pad on a bottom surface of theaccommodation space P.

The cover 60 of the present example may be formed in a flat plate shape.Accordingly, the cover 60 may be seated on an upper end surface of thepackage substrate 50 and bonded to the package substrate 50. Aconnection member 90 for bonding the cover 60 and the package substrate50 to each other may be interposed between the cover 60 and the packagesubstrate 50, but the configuration is not limited thereto.

As set forth above, since the bulk-acoustic wave resonator packageaccording to the various examples can minimize adsorption of particlesgenerated during the manufacturing process, fluctuations in the resonantfrequency can be minimized.

While this disclosure includes specific examples, it will be apparentafter an understanding of the disclosure of this application thatvarious changes in forms and details may be made in these exampleswithout departing from the spirit and scope of the claims and theirequivalents. The examples described herein are to be considered in adescriptive sense only, and not for purposes of limitation. Descriptionsof features or aspects in each example are to be considered as beingapplicable to similar features or aspects in other examples. Suitableresults may be achieved if the described techniques are performed in adifferent order, and/or if components in a described system,architecture, device, or circuit are combined in a different manner,and/or replaced or supplemented by other components or theirequivalents. Therefore, the scope of the disclosure is defined not bythe detailed description, but by the claims and their equivalents, andall variations within the scope of the claims and their equivalents areto be construed as being included in the disclosure.

What is claimed is:
 1. A bulk-acoustic wave resonator package, comprising: a package substrate; a cover bonded to the package substrate; an acoustic wave resonator accommodated in an accommodation space defined by the package substrate and the cover; a conductive wire disposed in the accommodation space and configured to electrically connect the acoustic wave resonator to the package substrate; and a bonding portion configured to fixedly couple the acoustic wave resonator to the package substrate, wherein the bonding portion comprises an adhesive member including silicon.
 2. The bulk-acoustic wave resonator package of claim 1, wherein the acoustic wave resonator comprises: a support substrate; a resonator comprising a first electrode, a piezoelectric layer, and a second electrode sequentially stacked on the support substrate; and a hydrophobic layer disposed along a surface of the resonator.
 3. The bulk-acoustic wave resonator package of claim 2, wherein a cavity is defined between the resonator and the support substrate, wherein the hydrophobic layer is disposed on an inner wall of the cavity.
 4. The bulk-acoustic wave resonator package of claim 2, wherein the hydrophobic layer comprises a self-assembled monolayer (SAM) forming material.
 5. The bulk-acoustic wave resonator package of claim 2, wherein the hydrophobic layer comprises a fluorine (F) component.
 6. The bulk-acoustic wave resonator package of claim 2, wherein the hydrophobic layer comprises fluorocarbon having a silicon head.
 7. The bulk-acoustic wave resonator package of claim 2, wherein the package substrate is comprises a ceramic substrate.
 8. The bulk-acoustic wave resonator package of claim 1, wherein the conductive wire comprises any one material of copper, gold, platinum, and aluminum.
 9. The bulk-acoustic wave resonator package of claim 2, further comprising: an insertion layer partially disposed in the resonator, and disposed between the first electrode and the piezoelectric layer, wherein the piezoelectric layer is at least partially raised by the insertion layer.
 10. The bulk-acoustic wave resonator package of claim 9, wherein the insertion layer comprises an inclined surface, wherein the piezoelectric layer comprises a piezoelectric portion disposed on the first electrode, and an inclined portion disposed on the inclined surface of the insertion layer.
 11. The bulk-acoustic wave resonator package of claim 10, wherein in a cross-section cut the resonator, an end of the second electrode is disposed on the inclined portion of the piezoelectric layer, or disposed along a boundary between the piezoelectric portion and the inclined portion.
 12. The bulk-acoustic wave resonator package of claim 10, wherein the piezoelectric layer comprises an extension portion disposed on an external side of the inclined portion, wherein at least a portion of the second electrode is disposed on the extension portion of the piezoelectric layer.
 13. The bulk-acoustic wave resonator package of claim 2, further comprising a Bragg reflective layer disposed below the resonator, wherein the Bragg reflective layer comprises a first reflective layer having a first acoustic impedance and a second reflective layer stacked on the first reflective layer and having a second acoustic impedance, which is lower than the first acoustic impedance.
 14. The bulk-acoustic wave resonator package of claim 2, wherein a groove-shaped cavity is disposed on an upper surface of the support substrate, wherein the resonator is spaced apart from the support substrate by the cavity.
 15. The bulk-acoustic wave resonator package of claim 2, further comprising a connection substrate disposed between the support substrate and the package substrate and mounted on the package substrate, wherein the bonding portion is interposed between the support substrate and the connection substrate.
 16. A bulk-acoustic wave resonator package, comprising: a package substrate; a support substrate bonded to the package substrate; a resonator disposed on the support substrate, and comprising a sequentially stacked first electrode, piezoelectric layer, and second electrode; a bonding wire electrically connecting the resonator to the package substrate; and a cover bonded to the package substrate and defining an accommodation space for accommodating the resonator, the support substrate, and the bonding wire, wherein a hydrophobic layer is disposed on a surface of the resonator. 